Dilation catheter tip removal instrument

ABSTRACT

A method of using an apparatus including a base housing, an actuator, and a blade. The base housing defines an upwardly presented support surface. The base housing also defines a distally oriented tip receiving recess. The distally oriented tip receiving recess is sized and configured to receive a bulbous distal tip of a dilation catheter. The actuator is movably coupled with the base housing. The blade us secured to the actuator. The actuator is operable to move the blade downwardly relative to the base housing. The blade is configured to sever a portion of a dilation catheter along a plane longitudinally interposed between the support surface and the tip receiving recess to thereby sever the bulbous distal tip of the dilation catheter in response to movement of the actuator relative to the base housing.

PRIORITY

This application claims priority to U.S. Provisional Pat. App. No.62/741,605, entitled “Dilation Catheter Tip Removal Instrument,” filedOct. 5, 2018, the disclosure of which is incorporated by referenceherein in its entirety.

BACKGROUND

In some instances, it may be desirable to dilate an anatomicalpassageway in a patient. This may include dilation of ostia of paranasalsinuses (e.g., to treat sinusitis), dilation of the larynx, dilation ofthe Eustachian tube, dilation of other passageways within the ear, nose,or throat, etc. One method of dilating anatomical passageways includesusing a guide wire and catheter to position an inflatable balloon withinthe anatomical passageway, then inflating the balloon with a fluid(e.g., saline) to dilate the anatomical passageway. For instance, theexpandable balloon may be positioned within an ostium at a paranasalsinus and then be inflated, to thereby dilate the ostium by remodelingthe bone adjacent to the ostium, without requiring incision of themucosa or removal of any bone. The dilated ostium may then allow forimproved drainage from and ventilation of the affected paranasal sinus.A system that may be used to perform such procedures may be provided inaccordance with the teachings of U.S. Pub. No. 2011/0004057, entitled“Systems and Methods for Transnasal Dilation of Passageways in the Ear,Nose or Throat,” published Jan. 6, 2011, now abandoned, the disclosureof which is incorporated by reference herein. An example of such asystem is the Relieva® Spin Balloon Sinuplasty™ System by Acclarent,Inc. of Irvine, California.

In the context of Eustachian tube dilation, a dilation catheter or otherdilation instrument may be inserted into the Eustachian tube and then beinflated or otherwise expanded to thereby dilate the Eustachian tube.The dilated Eustachian tube may provide improved ventilation from thenasopharynx to the middle ear and further provide improved drainage fromthe middle ear to the nasopharynx. Methods and devices for dilating theEustachian tube are disclosed in U.S. Patent Pub. No. 2010/0274188,entitled “Method and System for Treating Target Tissue within the ET,”published on Oct. 28, 2010, now abandoned, the disclosure of which isincorporated by reference herein; and U.S. Patent Pub. No. 2013/0274715,entitled “Method and System for Eustachian Tube Dilation,” published onOct. 17, 2013, now abandoned, the disclosure of which is incorporated byreference herein. An example of such a system is the Aera® EustachianTube Balloon Dilation System by Acclarent, Inc. of Irvine, California.

Some dilation catheters may be particularly configured to transitionbetween two modes particularly suited for two different kinds of medicalprocedures—one mode particularly suited for Eustachian tube dilationprocedures and another mode particularly suited for sinus ostiumdilation procedures. An example of such a dilation catheter is describedin U.S. Pub. No. 2017/0056632, entitled “Dilation Catheter withExpandable Stop Element,” published Mar. 2, 2017, issued as U.S. Pat.No. 10,512,763 on Dec. 24, 2019, the disclosure of which is incorporatedby reference herein.

While several systems and methods have been made and used in ENTprocedures, it is believed that no one prior to the inventors has madeor used the invention described in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments of the invention,and, together with the general description of the invention given above,and the detailed description of the embodiments given below, serve toexplain the principles of the present invention.

FIG. 1A depicts a perspective view of an exemplary dilation instrumentsystem including a dilation instrument having a guidewire and a dilationcatheter, showing the guidewire in a proximal position, and the dilationcatheter in a proximal position;

FIG. 1B depicts a perspective view of the dilation instrument system ofFIG. 1A, showing the guidewire in a distal position, and the dilationcatheter in the proximal position;

FIG. 1C depicts a perspective view of the dilation instrument system ofFIG. 1A, showing the guidewire in the distal position, the dilationcatheter in a distal position, and a dilator in a non-dilated state;

FIG. 1D depicts a perspective view of the dilation instrument system ofFIG. 1A, showing the guidewire in the distal position, the dilationcatheter in the distal position, and the dilator in a dilated state;

FIG. 2A depicts a schematic view of a guide catheter, guidewire, anddilation catheter of the dilation instrument system of FIG. 1A insertedthrough the nose of a patient, with the guidewire positioned in aparanasal sinus cavity, and the dilator being expanded to dilate anostium of the paranasal sinus cavity;

FIG. 2B depicts a schematic view of the patient of FIG. 2A, with theostium of the paranasal sinus cavity in a dilated state;

FIG. 3A depicts a cross-sectional view of a human ear showing the inner,middle and outer ear portions and the Eustachian tube connecting themiddle ear with the nasopharynx region of the throat;

FIG. 3B depicts a cross-sectional view of the human ear of FIG. 3A, withthe dilation catheter of the dilation instrument system of FIG. 1Ainserted in the Eustachian tube, and the dilator being expanded todilate the Eustachian tube;

FIG. 4 depicts a perspective view of a distal portion of an exemplaryalternative dilation catheter that may be readily incorporated into thedilation instrument system of FIG. 1A, with a bulb tip secured at thedistal end of the dilation catheter;

FIG. 5A depicts a side elevational view of the distal portion of thedilation catheter of FIG. 4 , with the bulb tip secured at the distalend of the dilation catheter, and with a guidewire at a proximalposition within the dilation catheter;

FIG. 5B depicts a side elevational view of the distal portion of thedilation catheter of FIG. 4 , with the bulb tip removed from the distalend of the dilation catheter, and with the guidewire at a proximalposition within the dilation catheter;

FIG. 5C depicts a side elevational view of the distal portion of thedilation catheter of FIG. 4 , with the bulb tip removed from the distalend of the dilation catheter, and with the guidewire at a distalposition such that a distal end of the guidewire is distal to the distalend of the dilation catheter;

FIG. 6 depicts a perspective view of an exemplary instrument that may beused to remove the bulb tip of the dilation catheter of FIG. 4 ;

FIG. 7 depicts an exploded perspective view of the instrument of FIG. 6;

FIG. 8 depicts a perspective view of an actuator and blade assembly ofthe instrument of FIG. 6 ;

FIG. 9 depicts another perspective view of the actuator and bladeassembly of FIG. 8 ;

FIG. 10 depicts an exploded perspective view of the actuator and bladeassembly of FIG. 8 ;

FIG. 11 depicts a perspective view of a base housing of the instrumentof FIG. 6 ;

FIG. 12 depicts a cross-sectional view of the base housing of FIG. 11 ,taken along line 12-12 of FIG. 11 ;

FIG. 13A depicts a perspective view of the dilation catheter of FIG. 4positioned for insertion in the instrument of FIG. 6 , with the actuatorand blade assembly in a pre-actuated state;

FIG. 13B depicts a perspective view of the dilation catheter of FIG. 4inserted into the instrument of FIG. 6 , with the actuator and bladeassembly in the pre-actuated state;

FIG. 13C depicts a perspective view of the dilation catheter of FIG. 4inserted into the instrument of FIG. 6 , with the actuator and bladeassembly in an actuated state;

FIG. 13D depicts a perspective view of the dilation catheter of FIG. 4inserted into the instrument of FIG. 6 , with the actuator and bladeassembly in a post-actuated state; and

FIG. 13E depicts a perspective view of the dilation catheter of FIG. 4removed from the instrument of FIG. 6 , with the actuator and bladeassembly in the post-actuated state.

The drawings are not intended to be limiting in any way, and it iscontemplated that various embodiments of the invention may be carriedout in a variety of other ways, including those not necessarily depictedin the drawings. The accompanying drawings incorporated in and forming apart of the specification illustrate several aspects of the presentinvention, and together with the description serve to explain theprinciples of the invention; it being understood, however, that thisinvention is not limited to the precise arrangements shown.

DETAILED DESCRIPTION

The following description of certain examples of the invention shouldnot be used to limit the scope of the present invention. Other examples,features, aspects, embodiments, and advantages of the invention willbecome apparent to those skilled in the art from the followingdescription, which is by way of illustration, one of the best modescontemplated for carrying out the invention. As will be realized, theinvention is capable of other different and obvious aspects, all withoutdeparting from the invention. Accordingly, the drawings and descriptionsshould be regarded as illustrative in nature and not restrictive.

For clarity of disclosure, the terms “proximal” and “distal” are definedherein relative to a surgeon, or other operator, grasping a surgicalinstrument having a distal surgical end effector. The term “proximal”refers to the position of an element arranged closer to the surgeon, andthe term “distal” refers to the position of an element arranged closerto the surgical end effector of the surgical instrument and further awayfrom the surgeon. Moreover, to the extent that spatial terms such as“upper,” “lower,” “vertical,” “horizontal,” or the like are used hereinwith reference to the drawings, it will be appreciated that such termsare used for exemplary description purposes only and are not intended tobe limiting or absolute. In that regard, it will be understood thatsurgical instruments such as those disclosed herein may be used in avariety of orientations and positions not limited to those shown anddescribed herein.

As used herein, the terms “about” and “approximately” for any numericalvalues or ranges indicate a suitable dimensional tolerance that allowsthe part or collection of components to function for its intendedpurpose as described herein.

I. EXEMPLARY DILATION INSTRUMENT SYSTEM

FIGS. 1A-1D show an exemplary dilation instrument system (10) that maybe used to dilate the ostium of a paranasal sinus in a human patient; todilate some other passageway associated with drainage of a paranasalsinus in a human patient; to dilate a Eustachian tube in a humanpatient; or to dilate some other anatomical passageway (e.g., within theear, nose, or throat, etc.) in a human patient. Dilation instrumentsystem (10) of this example comprises a guidewire power source (12), aninflation fluid source (14), an irrigation fluid source (16), and adilation instrument (20). In some versions, guidewire power source (12)comprises a source of light. In some other versions, guidewire powersource (12) is part of an image guided surgery (IGS) system. Inflationfluid source (14) may comprise a source of saline or any other suitablesource of fluid. Irrigation fluid source (16) may also comprise a sourceof saline or any other suitable source of fluid.

Dilation instrument (20) of the present example comprise a handle body(22) with a guidewire slider (24), a guidewire spinner (26), and adilation catheter slider (28). Handle body (22) is sized and configuredto be gripped by a single hand of a human operator. Sliders (24, 28) andspinner (26) are also positioned and configured to be manipulated by thesame hand that grasps handle body (22).

A guide catheter (60) extends distally from handle body (22). Guidecatheter (60) includes an open distal end (62) and a bend (64) formedproximal to open distal end (62). In some versions, dilation instrument(20) is configured to removably receive several different kinds of guidecatheters (60), each guide catheter (60) having a different angle formedby bend (64). Guide catheter (60) of the present example is formed of arigid material (e.g., rigid metal and/or rigid plastic, etc.), such thatguide catheter (60) maintains a consistent configuration of bend (64)during use of dilation instrument (20). In some versions, dilationinstrument (20), is further configured to enable rotation of guidecatheter (60), relative to handle body (22), about the longitudinal axisof the straight proximal portion of guide catheter (60), thereby furtherpromoting access to various anatomical structures.

By way of further example only, guide catheter (60) may be configuredand operable in accordance with at least some of the teachings of U.S.patent application Ser. No. 15/852,470, entitled “Dilation Instrumentwith Guide Catheter Type Sensor,” filed Dec. 22, 2017, now abandoned,the disclosure of which is incorporated by reference herein; U.S. Pub.No. 2017/0120020, entitled “Apparatus for Bending Malleable Guide ofSurgical Instrument,” published May 4, 2017, issued as U.S. Pat. No.10,137,286 on Nov. 27, 2019, the disclosure of which is incorporated byreference herein; and/or U.S. patent application Ser. No. 16/032,471,entitled “Adjustable Instrument for Dilation of Anatomical Passageway,”filed Jul. 11, 2018, issued as U.S. Pat. No. 10,874,839 on Dec. 29,2020, the disclosure of which is incorporated by reference herein.

A guidewire (30) is coaxially disposed in guide catheter (60). Guidewireslider (24) is secured to guidewire (30). Translation of guidewireslider (24) relative to handle body (22) from a proximal position (FIG.1A) to a distal position (FIG. 1B) thus causes corresponding translationof guidewire (30) relative to handle body (22) from a proximal position(FIG. 1A) to a distal position (FIG. 1B). When guidewire (30) is in adistal position, a distal portion of guidewire (30) protrudes distallyfrom open distal end (62) of guide catheter (60). Guidewire spinner (26)is operable to rotate guidewire (30) about the longitudinal axis ofguidewire (30). Guidewire spinner (26) is coupled with guidewire slider(24) such that guidewire spinner (26) translates longitudinally withguidewire slider (24).

By way of further example only, guidewire (30) may be configured andoperable in accordance with at least some of the teachings of U.S. Pub.No. 2018/0214216, entitled “Navigation Guidewire with InterlockedCoils,” published Aug. 2, 2018, issued as U.S. Pat. No. 10,610,308 onApr. 7, 2020, the disclosure of which is incorporated by referenceherein; U.S. Pat. No. 9,155,492, entitled “Sinus Illumination LightwireDevice,” issued Oct. 13, 2015, now abandoned, the disclosure of which isincorporated by reference herein; U.S. patent application Ser. No.15/852,530, entitled “Reusable Navigation Guidewire,” filed Dec. 22,2017, the disclosure of which is incorporated by reference herein; U.S.Pub. No. 2016/0008083, entitled “Guidewire Navigation for Sinuplasty,”published Jan. 14, 2016, issued as U.S. Pat. No. 10,463,242 on Nov. 5,2019, the disclosure of which is incorporated by reference herein;and/or U.S. Pub. No. 2014/0364725, entitled “Systems and Methods forPerforming Image Guided Procedures within the Ear, Nose, Throat andParanasal Sinuses,” published Dec. 11, 2014, now abandoned, thedisclosure of which is incorporated by reference herein.

A dilation catheter (40) is coaxially disposed in guide catheter (60).Dilation catheter slider (28) is secured to dilation catheter (40).Translation of dilation catheter slider (28) relative to handle body(22) from a proximal position (FIG. 1B) to a distal position (FIG. 1C)thus causes corresponding translation of dilation catheter (40) relativeto handle body (22) from a proximal position (FIG. 1B) to a distalposition (FIG. 1C). When dilation catheter (40) is in a distal position,a distal portion of dilation catheter (40) protrudes distally from opendistal end (62) of guide catheter (60). Dilation catheter (40) of thepresent example comprises a non-extensible balloon (44) located justproximal to open distal end (42) of dilation catheter (40). Balloon (44)is in fluid communication with inflation fluid source (14). Inflationfluid source (14) is configured to communicate fluid (e.g., saline,etc.) to and from balloon (44) to thereby transition balloon (44)between a non-inflated state and an inflated state. FIG. 1C showsballoon (44) in a non-inflated state. FIG. 1D shows balloon (44) in aninflated state. In the non-inflated state, balloon (44) is configured tobe inserted into a constricted anatomical passageway (e.g., paranasalsinus ostium, Eustachian tube, etc.). In the inflated state, balloon(44) is configured to dilate the anatomical passageway in which balloon(44) is inserted. Other features and operabilities that may beincorporated into dilation catheter (40) will be described in greaterdetail below.

In some versions, inflation fluid source (14) comprises a manuallyactuated source of pressurized fluid. In some such versions, themanually actuated source of pressurized fluid may be configured andoperable in accordance with at least some of the teachings of U.S. Pub.No. 2014/0074141, entitled “Inflator for Dilation of AnatomicalPassageway,” published Mar. 13, 2014, issued as U.S. Pat. No. 9,962,530on May 8, 2018, the disclosure of which is incorporated by referenceherein. Other suitable configurations that may be used to provide asource of pressurized fluid will be apparent to those of ordinary skillin the art in view of the teachings herein.

In some instances, it may be desirable to irrigate an anatomical site.For instance, it may be desirable to irrigate a paranasal sinus andnasal cavity after dilation catheter (40) has been used to dilate anostium or other drainage passageway associated with the paranasal sinus.Such irrigation may be performed to flush out blood, etc. that may bepresent after a dilation procedure. In some such cases, guide catheter(60) may be allowed to remain in the patient while guidewire (30) anddilation catheter (40) are removed. A dedicated irrigation catheter (notshown) may then be inserted into guide catheter (60) and coupled withirrigation fluid source (16) via irrigation tube (50), to enableirrigation of the anatomical site in the patient. By way of exampleonly, a dedicated irrigation catheter may be configured and operable inaccordance with at least some of the teachings of U.S. Pub. No.2008/0183128, entitled “Methods, Devices and Systems for Treatmentand/or Diagnosis of Disorders of the Ear, Nose and Throat,” publishedJul. 31, 2008, now abandoned, the disclosure of which is incorporated byreference herein.

II. EXEMPLARY DILATION PROCEDURES

As noted above, dilation instrument system (10) may be used to dilate adrainage passageway associated with a paranasal sinus, a Eustachiantube, and/or any other passageway in the ear, nose, or throat of apatient. The following describes two merely illustrative examples ofdilation procedures in which dilation instrument system (10) may beused. The following examples are not intended to be limiting. Otherprocedures in which dilation instrument system (10) may be used will beapparent to those of ordinary skill in the art in view of the teachingsherein.

A. Exemplary Sinus Ostium Dilation Procedure

FIGS. 2A-2B show portions of dilation instrument system (10) being usedin an exemplary procedure do dilate an ostium (O) of a maxillary sinus(MS) of a patient. As shown in FIG. 2A, guide catheter (60) ispositioned in the nasal cavity (NC) of the patient and is oriented todirect dilation catheter (40) into the ostium (O) of the maxillary sinus(MS). Guidewire (30) is advanced into the maxillary sinus (MS) at thestage depicted in FIG. 2A, and balloon (44) is inflated at the stagedepicted in FIG. 2A.

In the steps leading up to the stage depicted in FIG. 2A, dilationcatheter (40) may be fully retracted into guide catheter (60), andguidewire (30) may be retracted into dilation catheter (40), as guidecatheter (60) is initially inserted into the nasal cavity (NC). Guidecatheter (60) may then be manipulated to orient distal end (62) towardthe ostium (O) of the maxillary sinus (MS). This may be performed undervisualization from an endoscope or otherwise. Guidewire (30) may then beadvanced through the ostium (O) and into the maxillary sinus (MS). Inversions where guidewire (30) has an illuminating distal end, theposition of guidewire (30) in the maxillary sinus (MS) may be verifiedby observing transillumination effects through the cheek of the patientover the maxillary sinus (MS). In versions where guidewire (30) includesa navigation sensor, an image guided surgery navigation system (or otherkind of navigation system) may be used to verify that guidewire (30) isin the maxillary sinus (MS). Once guidewire (30) has been positioned,dilation catheter (40) may be advanced distally along guidewire (30),with further guidance from guide catheter (60), until balloon (44) ispositioned in the ostium (O) of the maxillary sinus (MS). The balloon(44) is then inflated to thereby dilate the ostium (O) of the maxillarysinus (MS).

After balloon (44) has been inflated and deflated a sufficient number oftimes within the ostium (O), dilation instrument system (10) is removedfrom the patient. The patient then has a dilated ostium (O) as shown inFIG. 2B. The dilated ostium (O) may provide improved ventilation to themaxillary sinus (MS) from the nasal cavity (NC) and/or improved drainagefrom the maxillary sinus (MS) into the nasal cavity (NC).

B. Exemplary Eustachian Tube Dilation Procedure

FIG. 3A shows anatomical structures associated with a patient's ear,including the outer ear (OE), the ear canal (EC), the tympanic membrane(TM), the middle ear (ME), and the Eustachian tube (ET). The Eustachiantube (ET) is in fluid communication with the nasopharynx via thepharyngeal ostium (PO). The isthmus (I) is a narrowed region (e.g.,approximately 1 mm in diameter) between the Eustachian tube (ET) and themiddle ear (ME). The Eustachian tube (ET) provides a pathway forventilation from the nasopharynx to the middle ear (ME); and fordrainage from the middle ear (ME) to the nasopharynx. When functioningproperly, the Eustachian tube (ET) may open for a fraction of a secondperiodically in response to swallowing or yawning. In so doing, itallows air into the middle ear (ME) to replace air that has beenabsorbed by the middle ear lining (mucous membrane) or to equalizepressure changes occurring on altitude changes. In instances where fluidis built up in the middle ear (ME), an opened Eustachian tube (ET) alsoprovides a pathway for such fluid to drain from the middle ear (ME) intothe nasopharynx.

In scenarios where the Eustachian tube (ET) remains persistently blockedor fails to open when it should, it may be desirable to dilate theEustachian tube (ET). As shown in FIG. 3B, this may be carried out usingdilation instrument system (10) by inserting guide catheter (60) througha patient's nose or mouth and positioning guide catheter (60) in thenasopharynx such that distal end (62) is oriented toward the pharyngealostium (PO). This may be performed under visualization from an endoscope(80), if desired. Dilation catheter (40) may be advanced through guidecatheter (60) to position balloon (44) within the Eustachian tube (ET),and the balloon (44) may then be inflated to thereby dilate theEustachian tube (ET).

When dilation catheter (40) is advanced through guide catheter (60) toposition balloon (44) within the Eustachian tube (ET), it may benecessary to take great care to avoid traversing the isthmus (I). Thismay ensure that instrumentation does not enter the middle ear (ME) andthereby damage the sensitive anatomical structures within the middle ear(ME). To that end, in the present example, guidewire (30) is notadvanced through Eustachian tube (ET) before dilation catheter (40) isadvanced into the Eustachian tube (ET). This is because guidewire (30)has a relatively small outer diameter, which may present a substantialrisk of guidewire (30) being accidentally advanced through the isthmus(I) and into the middle ear (ME). It may also be desirable to include astructural feature at the distal end of dilation catheter (40) toprevent the distal end of dilation catheter (40) from traversing theisthmus (I). An example of such a structural feature is described ingreater detail below.

III. EXEMPLARY ALTERNATIVE DILATION CATHETER

It may be desirable to provide a dilation instrument system (10) with asingle dilation catheter that may be used to dilate sinus ostia (0) andother passageways associated with drainage of paranasal sinus cavitiesand also a Eustachian tube. As noted above, it may be desirable toinclude a structural feature at the distal end of dilation catheter (40)to prevent the distal end of dilation catheter (40) from traversing theisthmus (I), thereby preventing the distal end of dilation catheter (40)from inadvertently damaging delicate anatomical structures in the middleear (ME). However, including such a structure on the distal end ofdilation catheter (40) prevent the distal end of dilation catheter fromtraversing a sinus ostium (O) or other passageway associated withdrainage of a paranasal sinus. In other words, in order to be largeenough to effectively prevent traversal of the isthmus (I), the distalend structure of dilation catheter (40) may be too large to pass througha sinus ostium (O) or other passageway associated with drainage of aparanasal sinus.

In view of the foregoing, it may be desirable to provide a version ofdilation catheter (40) that is capable of operating in two differentstructural modes—one with an enlarged distal end structure and one witha non-enlarged distal end structure. This may facilitate use of the samesingle dilation catheter in sinus ostium (O) dilation procedures and inEustachian tube (ET) dilation procedures, while preventing inadvertenttraversal of the isthmus (I) during Eustachian tube (ET) dilationprocedures, and while enabling traversal of a sinus ostium (O) duringsinus ostium (O) dilation procedures. Examples such variations ofdilation catheter (40) are described in greater detail below.

FIGS. 4-5C depict a distal portion of an exemplary alternative dilationcatheter (100). Dilation catheter (100) of this example may be readilyincorporated into dilation instrument system (10) in place of dilationcatheter (40). Dilation catheter (100) of this example comprises aflexible shaft (102) with a distal end (104). An inflatable balloon(106) is secured to shaft (102) near distal end (104). Flexible shaft(102) defines a guidewire lumen (110) that slidably receives guidewire(30). Flexible shaft (102) also defines an inflation lumen (not shown)that provides a pathway for communication of fluid between inflationfluid source (14) and balloon (106).

As shown in FIG. 4 , distal end (104) includes a bulbous tip (120),which is secured to the distal end of flexible shaft (102). Bulbous tip(120) includes a bulbous body (122) defining an opening (124). Bulbousbody (122) is sized such that bulbous body (122) is too large to passthrough an isthmus (I) between a Eustachian tube (ET) and a middle ear(ME). By way of example only, bulbous body (122) may have an outerdiameter that is larger than 1 mm, such as 2 mm, 3 mm, or larger. In anycase, bulbous body (122) has an outer diameter that is larger than theouter diameter of the distal portion of flexible shaft (102) to whichbulbous body (122) is secured. In some versions, bulbous body (122) isshaped like a blueberry. In some other versions, bulbous body (122) isspherical. Alternatively, bulbous body (122) may have any other suitableshape.

In the present example, bulbous body (122) is solid and is formed of amaterial (e.g., plastic, etc.) that has sufficient rigidity to preventbulbous body (122) from compressing when bulbous body (122) is pushedinto an isthmus (I) of a Eustachian tube (ET) via the Eustachian tube(ET). Bulbous body (122) is thus strong enough to provide a hard stopwhen an operator advances dilation catheter (100) into a Eustachian tube(ET) to the point where bulbous body (122) engages the isthmus (I).However, bulbous body (122) may still be soft enough to prevent damageto the isthmus (I) when bulbous body (122) engages the isthmus (I) whendilation catheter is inserted into the Eustachian tube (ET).

Opening (124) is in fluid communication with lumen (110) of shaft (102).Opening (124) and lumen (110) thus provide a ventilation pathway for theregion of the Eustachian tube (ET) that is distal to balloon (106) whenballoon (106) is inflated to dilate the Eustachian tube (ET). In someversions, the diameter of opening (124) is smaller than the outerdiameter of guidewire (30), such that bulbous tip (120) prevents distalend (32) of guidewire (30) from exiting distal end (104) of dilationcatheter (100) when bulbous tip (120) is secured at distal end (104) ofdilation catheter (100). By way of example only, in some versionsopening (124) has a diameter of approximately 0.8 mm, with guidewire(30) having an outer diameter of approximately 0.94 mm, and with lumen(110) having a diameter of at least approximately 1 mm.

Dilation catheter (100) also includes a mark (140) that provides avisual indication between the distal end of balloon (106) and theproximal end of bulbous tip (120). In some versions, mark (140) simplyprovides visual guidance to an operator where to cut dilation catheter(100) when the operator wishes to remove bulbous tip (120) as describedin greater detail below. In some other versions, dilation catheter (100)may also include perforations or other weakening structural featuresthat facilitate frangibly breaking bulbous tip (120) away from dilationcatheter (100).

FIGS. 4 and 5A show dilation catheter (100) in a mode where dilationcatheter (100) is particularly suited for use in procedures to dilatethe Eustachian tube (ET). In this mode, bulbous tip (120) is secured tothe distal end of shaft (102). When the operator advances dilationcatheter (100) into the Eustachian tube (ET) to thereby position balloon(106) into the Eustachian tube (ET), similar to what is shown in FIG.3B, bulbous body (122) may eventually engage the isthmus (I) therebyarresting further advancement of dilation catheter (100) into theEustachian tube (ET). This arresting of further advancement may furtherprovide tactile feedback to the operator, indicating that balloon (106)is positioned in the Eustachian tube (ET). The operator may then inflateballoon (106) to thereby dilate the Eustachian tube (ET). During thistime, to the extent that guidewire (30) is even positioned within lumen(110) of shaft (102), guidewire (30) may be positioned such that distalend (32) of guidewire (30) is proximal to bulbous tip (120).

After the operator has finished dilating the Eustachian tube (ET), theoperator may then wish to dilate a sinus ostium (O) or other passagewayassociated with drainage of a paranasal sinus. To facilitate such anoperation, the operator may remove bulbous tip (120) at mark (140). Insome instances, this removal may comprise cutting dilation catheter(100) at mark (140). In some other instances, this removal may comprisebreaking dilation catheter (100) at mark (140). In any case, afterbulbous tip (120) is removed, dilation catheter (100) may appear asshown in FIG. 5B. At this point, dilation catheter (100) as an opendistal end (150) that is proximal to the location where bulbous tip(120) was located. This open distal end (150) provides sufficientclearance for distal end (32) of guidewire (30) to pass freely throughopen distal end (150) of dilation catheter, as shown in FIG. 5C. Withdilation catheter (100) in the mode shown in FIGS. 5B-5C, distal end(150) may also pass through a sinus ostium (O) or other passagewayassociated with drainage of a paranasal sinus, thereby facilitating useof dilation catheter (100) to perform the procedure shown in FIG. 2A.

IV. EXEMPLARY INSTRUMENT FOR CUTTING DISTAL TIP OFF OF DILATION CATHETER

As noted above, dilation catheter (100) is configured to enable removalof bulbous tip (120) in order to transition dilation catheter (100) froma mode for dilating a Eustachian tube (ET) to a mode for dilating asinus ostium (O) or other passageway associated with drainage of aparanasal sinus. While it may be possible for an operator to use aconventional knife, scissors, or other cutting instrument to removebulbous tip (120), or even to break off bulbous tip (120), therelatively small size (e.g., diameter) of distal end (104) may make itsomewhat difficult for an operator to successfully sufficiently distalend (104) in order to remove bulbous tip (120). It may therefore bedesirable to provide an instrument that is dedicated to cutting bulboustip (120), with such an instrument providing sufficient stabilization todistal end (104) during the process and providing features that ensurethat distal end (104) is cut at the appropriate location to removebulbous tip (120) without damaging balloon (106) or other features ofdilation catheter. FIGS. 6-13E show an example of such an instrument(200).

Instrument (200) of the present example includes a base housing (210),an actuator (250), and a blade (290). Blade (290) is fixedly secured toactuator (250), which is slidably received in base housing (210). Eachof these components will be described in greater detail below. As willalso be described in greater detail below, distal end (104) of dilationcatheter (100) may be inserted into instrument (200), and then blade(290) may be driven by actuator (250) to sever bulbous tip (120) fromdistal end (104) while base housing (210) supports the rest of distalend (104).

As shown in FIGS. 6-7 and 11-12 , base housing (210) includes a supportsurface (212) defining a support recess (214), with a tip-receivingrecess (220) positioned distal to support recess (214). As described ingreater detail below, support surface (212) is configured to supportdistal end (104) of dilation catheter (100) when distal end (104) isinserted into instrument (200). Support recess (214) is configured toalign with tip-receiving recess (220) and thereby assist in guidingbulbous tip (120) into tip-receiving recess (220). In the presentexample, support recess (214) has a generally U-shaped profile. In someother versions, support recess (214) has a radiused or otherwise curvedprofile.

Base housing (210) further includes a pair of lateral channels (230),with retainer bosses (232) (FIG. 12 ) being positioned in respectivelateral channels (230). Base housing (210) also includes a pair of guidechannels (240) positioned distal to support recess (214) and proximal totip-receiving recess (220). Channels (230, 240) are configured tointeract with complementary features of actuator (250) as will bedescribed in greater detail below.

As shown in FIGS. 6-10 , actuator (250) of the present example includesan engagement flange (252), a lower recess (260), a pair of downwardlyprotruding guide prongs (262), and a pair of downwardly protruding latcharms (270). Engagement flange (252) is configured to be engaged by ahand of an operator to facilitate driving of actuator (250) downwardlytoward base housing (210) as will be described in greater detail below.Lower recess (260) is configured to complement support recess (214) andthereby provide clearance for a portion of distal end (104) of dilationcatheter (100) when actuator (250) is actuated to sever bulbous tip(120) from distal end (104). Guide prongs (262) are configured toslidably fit in guide channels (240) of base housing (210) to therebymaintain alignment between actuator (250) and base housing (210) asactuator (250) transitions between the non-actuated state and theactuated state. Latch arms (270) are configured to slidably fit inlateral channels (230) of base housing (210). The free end of each latcharm (270) includes a latch head (272), which is configured to engageretainer boss (232) in each corresponding lateral channel (230) of basehousing (210). Latch heads (272) and retainer bosses (232) cooperate torestrict upward movement of actuator (250) relative to base housing(210).

As shown in FIGS. 7-10 , blade (290) of the present example is aconventional single-edge razor blade, including a sharp edge (292), apair of lateral notches (294), and a central opening (296). As best seenin FIGS. 9-10 , blade (290) fits against a distal side of actuator(250). This side of actuator (250) includes a pair of lateral bosses(284) that fit in lateral notches (294) of blade (290); and a centralboss (286) that fits in central opening (296). Bosses (284, 286) fit innotches (924) and opening (296) to secure blade (290) to actuator (250)and maintain alignment of blade (290) relative to actuator (250). Thefit between blade (290) and actuator (250) provides exposure of sharpedge (292) relative to actuator (250).

FIGS. 13A-13E show instrument (200) being used to remove bulbous tip(120) from distal end (104) of dilation catheter (100). As shown in FIG.13A, the operator first aligns dilation catheter (100) such that distalend (104) lies on a common longitudinal axis with tip-receiving recess(220) of base housing (210). The operator then urges dilation catheter(100) distally to position bulbous tip (120) in tip-receiving recess(220), as shown in FIG. 13B. The portion of distal end (104) that isproximal to bulbous tip (120) rests on support surface (212) at supportrecess (214). The operator then engages engagement flange (252) ofactuator (250) and thereby urges actuator (250) downwardly while basehousing (210) and dilation catheter (100) remain stationary, as shown inFIG. 13C. As actuator (250) and blade (290) translate downwardly, sharpedge (292) severs distal end (104) to thereby cut off bulbous tip (120).As shown in FIG. 13C, with actuator (250) in the actuated state, lowerrecess (260) of actuator (250) provides clearance for portion of distalend (104) that is proximal to bulbous tip (120), thereby avoiding thecrushing of distal end (104) by actuator (250).

After achieving the actuated state shown in FIG. 13C, the operator maythen release actuator (250) or otherwise urge actuator (250) upwardly toreturn to the non-actuated position shown in FIG. 13D. In some versions,a spring or other resilient member (not shown) is disposed in basehousing (210) to resiliently bias actuator (250) to the non-actuatedposition. With bulbous tip (120) now severed from distal end (104), theoperator may remove dilation catheter (100) from instrument (200) asshown in FIG. 13E and use dilation catheter (100) in a medicalprocedure.

It should be understood that instrument (200) may be used in the processshown in FIGS. 13A-13E to transition dilation catheter (100) from a modefor dilating a Eustachian tube (ET) to a mode for dilating a sinusostium (O) or other passageway associated with drainage of a paranasalsinus. By providing the combination of support surface (212), supportrecess (214), and integral blade (290), instrument (200) maysubstantially improve the ease, quality, and consistency of cuttingbulbous tip (120) from distal end (104). Moreover, instrument (200) isconfigured to keep sharp edge (292) effectively covered or shielded,thereby preventing the operator from inadvertently cutting himself orherself with sharp edge (292) during operation of instrument (200).

V. EXEMPLARY COMBINATIONS

The following examples relate to various non-exhaustive ways in whichthe teachings herein may be combined or applied. It should be understoodthat the following examples are not intended to restrict the coverage ofany claims that may be presented at any time in this application or insubsequent filings of this application. No disclaimer is intended. Thefollowing examples are being provided for nothing more than merelyillustrative purposes. It is contemplated that the various teachingsherein may be arranged and applied in numerous other ways. It is alsocontemplated that some variations may omit certain features referred toin the below examples. Therefore, none of the aspects or featuresreferred to below should be deemed critical unless otherwise explicitlyindicated as such at a later date by the inventors or by a successor ininterest to the inventors. If any claims are presented in thisapplication or in subsequent filings related to this application thatinclude additional features beyond those referred to below, thoseadditional features shall not be presumed to have been added for anyreason relating to patentability.

Example 1

An apparatus comprising: (a) base housing defining: (i) an upwardlypresented support surface, and (ii) a distally oriented tip receivingrecess, wherein the distally oriented tip receiving recess is sized andconfigured to receive a bulbous distal tip of a dilation catheter; (b)an actuator movably coupled with the base housing; and (c) a bladesecured to the actuator, wherein the actuator is operable to move theblade downwardly relative to the base housing, wherein the blade isconfigured to sever a portion of a dilation catheter along a planelongitudinally interposed between the support surface and the tipreceiving recess to thereby sever the bulbous distal tip of the dilationcatheter in response to movement of the actuator relative to the basehousing.

Example 2

The apparatus of Example 1, wherein the upwardly presented supportsurface defines a downwardly extending support recess, wherein thedownwardly extending support recess is positioned to correspond with thedistally oriented tip receiving recess.

Example 3

The apparatus of Example 2, wherein the downwardly extending supportrecess has a generally U-shaped profile.

Example 4

The apparatus of any one or more of Examples 2 through 3, wherein theactuator defines an upwardly extending lower recess, wherein theupwardly extending lower recess is positioned to correspond with thedownwardly extending support recess.

Example 5

The apparatus of any one or more of Examples 1 through 4, wherein theactuator is operable to translate downwardly relative to the basehousing to thereby drive the blade downwardly relative to the basehousing.

Example 6

The apparatus of Example 5, wherein the actuator comprises a flangeconfigured for engagement by an operator to drive the actuatordownwardly relative to the base housing.

Example 7

The apparatus of any one or more of Examples 1 through 6, wherein thebase housing further includes a pair of lateral channels, wherein thelateral channels of the base housing are configured to receivecorresponding lateral portions of the actuator.

Example 8

The apparatus of Example 7, wherein the lateral portions of the actuatorcomprise latch arms configured to fit in the lateral channels of thebase housing.

Example 9

The apparatus of Example 8, wherein each latch arm comprises a latchhead, wherein each lateral channel comprises a retainer boss, whereinthe retainer bosses are configured to cooperate with the latch heads torestrict upward movement of the actuator relative to the base housing.

Example 10

The apparatus of any one or more of Examples 1 through 9, wherein theblade includes a sharp edge, wherein the sharp edge is configured totraverse an axis extending proximally from the distally oriented tipreceiving recess.

Example 11

The apparatus of Example 10, wherein the base housing and the actuatorare configured to shield the sharp edge of the blade.

Example 12

The apparatus of any one or more of Examples 1 through 11, wherein theblade defines one or both of notches or an opening, wherein the actuatordefines at least one boss configured to fit in the one or both ofnotches or an opening to thereby secure the blade relative to theactuator.

Example 13

The apparatus of any one or more of Examples 1 through 12, furthercomprising a dilation catheter having a bulbous tip, the bulbous tipbeing configured to fit in the distally oriented tip receiving recess ofthe base housing.

Example 14

The apparatus of Example 13, wherein the bulbous tip is configured tofit in a medial region of a Eustachian tube of a human patient, whereinthe bulbous tip is configured to not pass through an isthmus of aEustachian tube of a human patient.

Example 15

The apparatus of any one or more of Examples 13 through 14, wherein adistal portion of the dilation catheter that is proximal to the bulbousdistal tip is configured to pass through an ostium of a paranasal sinusof a human patient.

Example 16

An apparatus, comprising: (a) a dilation catheter, the dilation cathetercomprising: (i) a shaft, (ii) a dilator at a distal portion of theshaft, and (iii) a bulbous distal tip secured to the shaft at a locationdistal to the dilator; and (b) a cutting instrument, the cuttinginstrument comprising: (i) a base housing, the base housing defining:(A) a support surface configured to support the distal portion of theshaft, and (B) a tip receiving recess configured to receive the bulboustip while the support surface supports the distal portion of the shaft,(ii) an actuator movably coupled with the base housing, and (iii) ablade secured to the actuator, wherein the actuator is operable to drivethe blade to sever the bulbous distal tip from the shaft while thesupport surface supports the distal portion of the shaft and while thebulbous tip is received in the tip receiving recess.

Example 17

The apparatus of Example 16, wherein the support surface is upwardlypresented, wherein the actuator is operable to move downwardly relativeto the base housing to thereby drive the blade to sever the bulbousdistal tip from the shaft.

Example 18

A method, comprising: (a) inserting a distal end of a dilation catheterinto a cutting instrument, wherein the cutting instrument includes: (i)a base housing, the base housing defining a distally oriented tipreceiving recess, (ii) an actuator movably coupled with the basehousing, and (iii) a blade secured to the actuator; (b) actuating theactuator to thereby drive the blade to sever a distal tip from thedilation catheter; and (c) removing the distal end of the dilationcatheter from the cutting instrument.

Example 19

The method of Example 18, wherein the distal tip is bulbous, wherein theremoved distal end has a smaller outer diameter than the inserted distalend due to the severing of the bulbous distal tip from the dilationcatheter.

Example 20

The method of any one or more of Examples 18 through 19, furthercomprising: (a) using the dilation catheter to dilate a Eustachian tubeof a patient before the act of inserting; and (b) using the dilationcatheter to dilate a passageway associated with drainage of a paranasalsinus of the patient after the act of removing.

VI. MISCELLANEOUS

It should be understood that any one or more of the teachings,expressions, embodiments, examples, etc. described herein may becombined with any one or more of the other teachings, expressions,embodiments, examples, etc. that are described herein. Theabove-described teachings, expressions, embodiments, examples, etc.should therefore not be viewed in isolation relative to each other.Various suitable ways in which the teachings herein may be combined willbe readily apparent to those of ordinary skill in the art in view of theteachings herein. Such modifications and variations are intended to beincluded within the scope of the claims.

It should be appreciated that any patent, publication, or otherdisclosure material, in whole or in part, that is said to beincorporated by reference herein is incorporated herein only to theextent that the incorporated material does not conflict with existingdefinitions, statements, or other disclosure material set forth in thisdisclosure. As such, and to the extent necessary, the disclosure asexplicitly set forth herein supersedes any conflicting materialincorporated herein by reference. Any material, or portion thereof, thatis said to be incorporated by reference herein, but which conflicts withexisting definitions, statements, or other disclosure material set forthherein will only be incorporated to the extent that no conflict arisesbetween that incorporated material and the existing disclosure material.

Versions of the devices described above may be designed to be disposedof after a single use, or they can be designed to be used multipletimes. Versions may, in either or both cases, be reconditioned for reuseafter at least one use. Reconditioning may include any combination ofthe steps of disassembly of the device, followed by cleaning orreplacement of particular pieces, and subsequent reassembly. Inparticular, some versions of the device may be disassembled, and anynumber of the particular pieces or parts of the device may beselectively replaced or removed in any combination. Upon cleaning and/orreplacement of particular parts, some versions of the device may bereassembled for subsequent use either at a reconditioning facility, orby a user immediately prior to a procedure. Those skilled in the artwill appreciate that reconditioning of a device may utilize a variety oftechniques for disassembly, cleaning/replacement, and reassembly. Use ofsuch techniques, and the resulting reconditioned device, are all withinthe scope of the present application.

By way of example only, versions described herein may be sterilizedbefore and/or after a procedure. In one sterilization technique, thedevice is placed in a closed and sealed container, such as a plastic orTYVEK bag. The container and device may then be placed in a field ofradiation that can penetrate the container, such as gamma radiation,x-rays, or high-energy electrons. The radiation may kill bacteria on thedevice and in the container. The sterilized device may then be stored inthe sterile container for later use. A device may also be sterilizedusing any other technique known in the art, including but not limited tobeta or gamma radiation, ethylene oxide, or steam.

Having shown and described various embodiments of the present invention,further adaptations of the methods and systems described herein may beaccomplished by appropriate modifications by one of ordinary skill inthe art without departing from the scope of the present invention.Several of such potential modifications have been mentioned, and otherswill be apparent to those skilled in the art. For instance, theexamples, embodiments, geometrics, materials, dimensions, ratios, steps,and the like discussed above are illustrative and are not required.Accordingly, the scope of the present invention should be considered interms of the following claims and is understood not to be limited to thedetails of structure and operation shown and described in thespecification and drawings.

We claim:
 1. A method of using an apparatus, the apparatus comprising:(a) base housing defining: (i) an upwardly presented support surfaceconfigured to support and contact a distal end of a dilation catheter,the upwardly presented support surface forming a channel such that anupper portion of the distal end of the dilation catheter isunconstrained above the upwardly presented support surface by the basehousing, and (ii) a distally oriented tip receiving recess tip receivingrecess being sized and configured to receive a bulbous distal tip of thedilation catheter, the support surface being aligned with the receivingrecess and is thereby positioned and configured to guide the bulbousdistal tip of the dilation catheter into the receiving recess; (b) anactuator movably coupled with the base housing; and (c) a blade securedto the actuator; the method comprising: (a) using the dilation catheterto dilate a Eustachian tube of a patient; (b) inserting the bulbousdistal tip of the dilation catheter into the distally oriented tipreceiving recess of the apparatus; (c) actuating the actuator to therebydrive the blade downwardly relative to the base housing to sever thebulbous distal tip from the dilation catheter along a planelongitudinally interposed between the support surface and the tipreceiving recess; (d) removing the dilation catheter from the apparatus;and (e) using the dilation catheter to dilate a passageway associatedwith drainage of a paranasal sinus of the patient after the act ofremoving.
 2. The method of claim 1, arranging the upwardly presentedsupport surface defining a downwardly extending support recess and thedownwardly extending support recess being positioned to correspond withthe distally oriented tip receiving recess.
 3. The method of claim 2,providing the downwardly extending support recess having a generallyU-shaped profile.
 4. The method of claim 2, providing the actuator withan upwardly extending lower recess being positioned to correspond withthe downwardly extending support recess.
 5. The method of claim 1,operating the actuator to translate downwardly relative to the basehousing to thereby drive the blade downwardly relative to the basehousing.
 6. The method of claim 5, providing the actuator with a flangeconfigured for engagement by an operator to drive the actuatordownwardly relative to the base housing.
 7. The method of claim 1,providing the base housing with a pair of lateral channels receivingcorresponding lateral portions of the actuator.
 8. The method of claim7, providing lateral portions of the actuator with latch arms fitting inthe lateral channels of the base housing.
 9. The method of claim 8,providing each latch arm with a latch head and each lateral channelcomprising a retainer boss cooperating with the latch heads to restrictupward movement of the actuator relative to the base housing.
 10. Themethod of claim 1, providing the blade with a sharp edge configured totraverse an axis extending proximally from the distally oriented tipreceiving recess.
 11. The method of claim 10, shielding the sharp edgeof the blade by the base housing and the actuator.
 12. The method ofclaim 1, providing the blade with one or both of notches or an openingand the actuator including at least one boss fitting in the one or bothof notches or an opening to thereby secure the blade relative to theactuator.
 13. The method of claim 1, fitting the bulbous distal tip in amedial region of a Eustachian tube of a human patient, the bulbousdistal tip being configured to not pass through an isthmus of aEustachian tube of a human patient.
 14. The method of claim 1,positioning a distal portion of the dilation catheter that is proximalto the bulbous distal tip to pass through an ostium of a paranasal sinusof a human patient.
 15. A method of using an apparatus, the apparatus,comprising: (a) a dilation catheter, the dilation catheter comprising:(i) a shaft, (ii) a dilator at a distal portion of the shaft, and (iii)a bulbous distal tip secured to the shaft at a location distal to thedilator, the bulbous distal tip being configured to prevent the distalportion of the shaft from otherwise traversing a sinus ostium or anisthmus between a Eustachian tube and a middle ear, the distal portionof the shaft being configured to traverse the sinus ostium in theabsence of the bulbous distal tip; and (b) a cutting instrument, thecutting instrument comprising: (i) a base housing, the base housingdefining: (A) a support surface configured to support the distal portionof the shaft, (B) a tip receiving recess configured to receive thebulbous tip while the support surface supports the distal portion of theshaft, (C) a first guide channel positioned adjacent to a first side ofthe support surface, and (D) a second guide channel positioned adjacentto a second side of the support surface, (ii) an actuator movablycoupled with the base housing, the actuator including: (A) a first guideprong, the first guide channel being configured to slidably receive thefirst guide prong, and (B) a second guide prong, the second guidechannel being configured to slidably receive the second guide prong, thefirst guide channel, the first guide prong, the second guide channel,and the second guide prong being configured to cooperate to maintainalignment between the base housing and the actuator, and (iii) a bladeincluding an opening, the actuator being secured to the blade at theopening, the actuator being operable to drive the blade to sever thebulbous distal tip from the shaft while the support surface supports thedistal portion of the shaft and while the bulbous tip is received in thetip receiving recess, the distal portion of the shaft being configuredto traverse the sinus ostium after the bulbous distal tip is severedfrom the shaft by the cutting instrument; the method comprising: (a)using the dilation catheter to dilate a Eustachian tube of a patient;(b) inserting the bulbous distal tip of the dilation catheter into thetip receiving recess of the cutting instrument; (c) actuating theactuator to thereby drive the blade to sever the bulbous distal tip fromthe dilation catheter; (d) removing the dilation catheter from thecutting instrument; and (e) using the dilation catheter to dilate apassageway associated with drainage of a paranasal sinus of the patientafter the act of removing.
 16. The method of claim 15, moving theactuator downwardly relative to the base housing to thereby drive theblade to sever the bulbous distal tip from the shaft.
 17. A method,comprising: (a) using a dilation catheter to dilate a Eustachian tube ofa patient; (b) inserting a distal end of the dilation catheter into acutting instrument after using the dilation catheter to dilate theEustachian tube of the patient, the cutting instrument including: (i) abase housing, the base housing defining a distally oriented tipreceiving recess, (ii) an actuator movably coupled with the basehousing, and (iii) a blade secured to the actuator; (c) actuating theactuator to thereby drive the blade to sever a distal tip from thedilation catheter; (d) removing the distal end of the dilation catheterfrom the cutting instrument; and (e) using the dilation catheter todilate a passageway associated with drainage of a paranasal sinus of thepatient after the act of removing.
 18. The method of claim 17, providingthe distal tip being bulbous, the removed distal end having a smallerouter diameter than the inserted distal end due to the severing of thebulbous distal tip from the dilation catheter.
 19. The method of claim17, including a mark on the dilation catheter for indicating where tosever the distal tip form the dilation catheter.